Millimeter wave module and radio apparatus

ABSTRACT

A millimeter wave module includes a silicon substrate with first and second cavityes formed by anisotropic etching on the silicon substrate, and a glass substrate having a microstrip filter pattern and microbumps for connecting the glass substrate to the silicon substrate. A filter is provided using an air layer as a dielectric disposed in the first cavity. An MMIC is mounted by the flip chip method over the second air layer. A coplanar waveguide is on the silicon substrate for connecting the filter and MMIC. The filter having low loss is achieved because it has the microstrip structure using air as an insulating layer. Also change in characteristics of the MMIC during mounting is eliminated because the MMIC is protected by contacting air. Accordingly, the millimeter wave module has excellent characteristics and is made using a simple method.

FIELD OF THE INVENTION

[0001] The present invention relates to the field of high frequencymodules using millimeter waves or microwaves, and radio apparatusesemploying such modules.

BACKGROUND OF THE INVENTION

[0002] One known millimeter waveguide using anisotropically etchedsilicon substrate is disclosed in IEEE MTT-S Digest pp. 797-800, 1996.

[0003]FIG. 10 shows the structure of a conventional millimeter wavetransmission line. Silicon dioxide (SiO₂) 902 is deposited on a siliconsubstrate 901, and a microstrip line 903 is formed on the silicondioxide 902. A shielded microstrip line is created by sandwiching thesilicon substrate 901 between a carrier substrate 904 coated with metalfilm, and another silicon substrate 905 processed by micromachining, toachieve a shielding structure. With this shielding structure, which usesair as the dielectric medium, a transmission line with low loss can beachieved.

[0004] In this type of millimeter transmission line, however,modularization by mounting other millimeter wave components such as anMMIC (Monolithic Microwave Integrated Circuit) may be difficult, becausethe microstrip line is supported by silicon dioxide in midair. There mayalso be a problem with strength. Two sheets of silicon substrate areprocessed by micromachining, and an unduly thick silicon dioxide filmmust be formed to ensure strength. These result in the need forcomplicated processing during manufacturing.

SUMMARY OF THE INVENTION

[0005] The present invention offers an inexpensive millimeter wave andmicrowave apparatus by facilitating processing of a millimeter wavemodule in which components such as a low-loss filter and MMIC aremounted.

[0006] A millimeter wave module of the present invention comprises firstand second substrates. The first substrate comprises a cavity on oneflat face, a conductor formed on the bottom and side faces of thecavity, a connection part formed on a flat face around the cavity andelectrically connected to the conductor formed in the cavity, and an airlayer inside the cavity. The second substrate made of dielectricscomprises, on one flat face, metal patterning of a microstrip filter anda connection part connected to the metal patterning. The secondsubstrate is mounted on the first substrate, so that the connection partof the first substrate is attached to the connection part connected tothe metal patterning of the second substrate, and that the metalpatterning of the second substrate faces the air layer in the cavity ofthe first substrate and also covers the cavity.

[0007] With this configuration, a low-loss filter using air asdielectric loss free materials may be easily achieved, and a device faceof MMIC may be protected without any degradation. In addition, alow-loss filter and MMIC may be easily connected.

[0008] Using a millimeter wave module manufactured in accordance withthe above simple method, an inexpensive radio apparatus may be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1A is a sectional view of a structure of a millimeter wavemodule in accordance with a first exemplary embodiment of the presentinvention.

[0010]FIG. 1B is a conceptual perspective view of the millimeter wavemodule in accordance with the first exemplary embodiment of the presentinvention.

[0011]FIG. 2A is a sectional view of a structure of a millimeter wavemodule in accordance with a second exemplary embodiment of the presentinvention.

[0012]FIG. 2B is a structural view of the surface and rear faces of aglass substrate used in the millimeter wave module in accordance withthe second exemplary embodiment of the present invention.

[0013]FIG. 3 is a sectional view of a structure of a millimeter wavemodule in accordance with a third exemplary embodiment of the presentinvention.

[0014]FIG. 4 is a sectional view of a structure of a millimeter wavemodule in accordance with a fourth exemplary embodiment of the presentinvention.

[0015]FIG. 5 is a sectional view of a structure of a millimeter wavemodule in accordance with a fifth exemplary embodiment of the presentinvention.

[0016]FIG. 6A is a sectional view of a structure of a millimeter wavemodule in accordance with a sixth exemplary embodiment of the presentinvention.

[0017]FIG. 6B is a conceptual perspective view of a millimeter wavemodule in accordance with a sixth exemplary embodiment of the presentinvention.

[0018]FIG. 7A is a sectional view of a structure of a millimeter wavemodule in accordance with a seventh exemplary embodiment of the presentinvention.

[0019]FIG. 7B is a conceptual perspective view of a silicon substrateused in the millimeter wave module in accordance with the seventhexemplary embodiment of the present invention.

[0020]FIG. 8 is a structural view of a surface of a glass substrate usedin the millimeter wave module in accordance with the seventh exemplaryembodiment of the present invention.

[0021]FIG. 9 is a radio apparatus in accordance with an eighth exemplaryembodiment of the present invention.

[0022]FIG. 10 is a sectional view of a structure of a conventionalmillimeter wave transmission line.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention offers a low-loss filter using an air layeras dielectric loss free materials by mounting a dielectric substratehaving a metal pattern onto a semiconductor substrate having multiplecavityes and a metal pattern on its surface. Mounting of othermillimeter wave components is also facilitated. Since the use of a thinsilicon dioxide film which has insufficient mechanical strength iseliminated, the millimeter wave module may be easily manufactured.Exemplary embodiments of the present invention are described below withreference to FIGS. 1 to 9.

[0024] First Exemplary Embodiment

[0025] A millimeter wave module in a first exemplary embodiment of thepresent invention is described with reference to FIGS. 1A and 1B.

[0026] Multiple rectangular cavities 102 a and 102 b are formed byanisotropic etching on a surface of a silicon single crystal substrate101. Metal ground layers 103 a and 103 b are deposited on the bottom andside faces, as ground plane, of each of the cavityes 102 a and 102 b. Acoplanar waveguide 108 is formed on the flat face around the cavityes102 a and 102 b on the surface of the silicon single crystal substrate101, in order to connect metal ground layers 103 a and 103 b in thecavityes 102 a and 102 b, and to act as I/O terminals. Connection partsare also formed on the flat face around the cavityes 102 a and 102 b forthe use in mounting. These connection parts are electrically connectedto the metal ground layers 103 a and 103 b formed in the cavityes 102 aand 102 b. Air layers 104 a and 104 b exist inside the cavityes 102 aand 102 b.

[0027] Metal patterning 109 for the microstrip filter is formed on oneface of a glass substrate 107, which comprises the dielectric substrate,and Au microbumps 105 are provided at the periphery of the metalpatterning 109, for the use in mounting, as a connection part for themetal patterning 109.

[0028] Other Au microbumps 105 for the use in mounting are formed at theperiphery of an MMIC 106.

[0029] The glass substrate 107 is mounted on the silicon single crystalsubstrate 101, through the Au bumps 105, so that the metal patterning109 of the microstrip filter of the glass substrate 107 faces the airlayer 104 a and covers the cavity 102 a of the silicon substrate 101.

[0030] The millimeter wave MMIC 106 is mounted above the cavity 102 bthrough the Au bumps so as to cover the cavity 102 b.

[0031] In other words, the metal patterning 109 of the microstrip filterand millimeter MMIC 106 are configured to respectively face the airlayers 104 a and 104 b. The metal patterning 109 of the microstripfilter and millimeter MMIC 106 are also connected to the coplanarwaveguide 108 through the Au bumps 105. A bias pad 110 supplies bias tothe MMIC 106.

[0032] With the above structure, the electric field of the microstripfilter is mostly concentrated on the air layer 104 a which has nodielectric loss, enabling the creation of a low-loss filter.

[0033] In addition, the cavity 102 b is also provided on the siliconsubstrate 101 directly under the millimeter MMIC to be mounted so as toform the air layer 104 b near an active element. Mounting through the Aubumps 105 enables the achievement of high mounting position accuracy,suppressing any deterioration of its characteristics.

[0034] Furthermore, provision of the coplanar waveguide 108 forconnecting the glass substrate 107 and MMIC 106 enables thesimplification of processing of the silicon substrate 101.

[0035] Consequently, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured according to the abovesimple method.

[0036] The first exemplary embodiment describes the configuration of theone filter and one MMIC. However, more than one filter and MMIC may becombined in many ways.

[0037] In this exemplary embodiment, cavityes are processed byanisotropic etching. It is apparent that the same shape is achievable bydry etching.

[0038] Second Exemplary Embodiment

[0039]FIGS. 2A and 2B are conceptual views of a structure of amillimeter wave module in a second exemplary embodiment of the presentinvention. FIG. 2A is a sectional view, and FIG. 2B, shows the state ofthe surface and rear faces. The difference with the first exemplaryembodiment and FIGS. 2A and 2B is that a ground plane 111 is provided onthe rear face of the glass substrate 107 on which the metal patterning109 of the microstrip filter is not formed. This ground plane 111 isconnected to the metal ground layer 103 a of the silicon substrate 101through a through hole 112. Other components are the same as those inFIG. 1, and thus detailed explanation is omitted here.

[0040] With the above configuration, an electric field generated nearthe metal patterning 109 of the microstrip filter is shielded bysurrounding it with the metal ground layer 103 a and ground plane 111from the top and bottom. This suppresses loss or deterioration byradiation of the electric field. At the same time, change in the filtercharacteristics may be prevented when the millimeter wave module of thepresent invention is packaged onto the housing.

[0041] Furthermore, shielding of the metal patterning of the filter bytop and bottom ground planes prevents radiation of the electric field.

[0042] Consequently, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured according to the abovesimple method.

[0043] Third Exemplary Embodiment

[0044]FIG. 3 shows a conceptual view of a sectional structure of amillimeter wave module in a third exemplary embodiment of the presentinvention. The difference with the first exemplary embodiment in FIG. 3is that a third substrate 201 (201 a, 201 b, and 201 c) is employedinstead of the silicon substrate 101. The same shape of cavity as on thesilicon substrate 101 is formed on the third substrate 201 by laminatingtwo layers of first ceramic substrates 201 b and 201 c, on which arectangular hole is provided, and a second ceramic substrate 201 awithout a hole. Ground layers 203 a and 203 b are deposited on thebottom and side faces of the cavityes to form air layers 204 a and 204b. Other components are the same as those in FIG. 1, and thus detailedexplanation is omitted here.

[0045] With the above configuration, the same effect as produced by thefirst exemplary embodiment is achievable by the use of inexpensiveceramic substrate.

[0046] In the third exemplary embodiment, two layers of ceramicsubstrates 201 b and 201 c configure the first ceramic substrate. Thisconfiguration facilitates the adjustment of the thickness of the airlayers as required, i.e., the thickness of the air layer 204 acorresponds to two ceramic layers and the thickness of the air layer 204b corresponds to one ceramic layer.

[0047] In this exemplary embodiment, the third ceramic substrate 201 ismade of three layers. However, it is apparent that the same effect isachievable with four layers or more.

[0048] Also in this exemplary embodiment, an organic material such asBCB (benzocyclobutene) or polyimide may be used as the dielectricsinstead of the ceramic substrate. As a result of the use of organicmaterial, more accurate dimensions for cavityes may be achieved thanwith the ceramic substrate, enabling the further improvement ofmillimeter wave characteristics.

[0049] Accordingly, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured using the above simplemethod.

[0050] Fourth Exemplary Embodiment

[0051]FIG. 4 is a conceptual view of a sectional structure of amillimeter wave module in a fourth exemplary embodiment of the presentinvention. The difference with the third exemplary embodiment in FIG. 4is that a ground plane 205 is provided between bonded faces of thesecond ceramic substrate 201 a without hole and one of the first ceramicsubstrate 201 b with hole. The ground layer 203 b provided on the bottomand side faces of the cavity and a ground plane 205 are connected by athrough hole 210 so as to connect between the glass substrate 107 andMMIC 106 not with the coplanar waveguide instead of the microstrip line.Other components are the same as those in FIG. 1, and thus detailedexplanation is omitted here. With the above configuration, variouscomponents such as a filter and MMIC may be connected using themicrostrip line instead of the coplanar waveguide, eliminating the needof a converter between the coplanar and microstrip lines, and thusfacilitating designing.

[0052] Consequently, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured using the above simplemethod.

[0053] Fifth Exemplary Embodiment

[0054]FIG. 5 is a conceptual view of a sectional structure of amillimeter wave module in a fifth exemplary embodiment of the presentinvention. The difference with the fourth exemplary embodiment in FIG. 5is that a conductive metal 206 such as aluminum or brass is used insteadof the ceramic substrate 201 a without hole. Other components are thesame as those in FIG. 4, and thus detailed explanation is omitted here.With the above configuration, an inexpensive module with a simplestructure and the same effect as the fourth exemplary embodiment may beachieved.

[0055] Consequently, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured using the above simplemethod.

[0056] Sixth Exemplary Embodiment

[0057]FIGS. 6A and 6B are conceptual views of a structure of amillimeter wave module in a sixth exemplary embodiment of the presentinvention. FIG. 6A is a sectional view and FIG. 6B is a perspectiveview.

[0058] Metal patterning 309 of a microstrip filter and a coplanarwaveguide 308 are formed on a glass substrate 301, and a rectangularhole 311 is provided on the glass substrate 301. This rectangular hole311 may be either a through hole or cavity.

[0059] A cavity 303 formed by anisotropic etching is created on asilicon substrate 302, and a metal ground layer 304 is deposited as aground face on the bottom and side faces of the cavity 303. In addition,an Au microbumps 306 is formed on a flat face around the cavity 303, forthe use in mounting, as a connection part electrically connected to themetal ground layer 304 formed on the cavity 303. An air layer 305 existsin the cavity 303.

[0060] Another Au microbumps 306 for the use in mounting is formed atthe periphery of a MMIC 307.

[0061] The silicon substrate 302 is mounted onto the glass substrate 301through the Au microbumps 306, and the metal ground layer 304 depositedin the cavity 304 is connected to the coplanar waveguide 308. Themillimeter wave MMIC 307 is mounted on the glass substrate 301 throughthe Au microbumps 306, and connected to the coplanar waveguide 308, alsothrough the Au microbumps 306. A bias pad 310 supplies bias to themillimeter MMIC 307.

[0062] With the above configuration, the microstrip filter using the airlayer 305 as an insulating layer is achieved, same as in the firstexemplary embodiment, and thus a low-loss filter is realized.

[0063] By providing a rectangular hole 311 on the glass substrate 301directly under the mounted millimeter MMIC 307, an active element mayface with air. This enables to suppress deterioration in characteristicsof the MMIC, which may be caused by mounting through the Au microbumps.

[0064] Consequently, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured using the above simplemethod.

[0065] Seventh Exemplary Embodiment

[0066]FIGS. 7A, 7B, and 8 show the conceptual structure of a millimeterwave module in a seventh exemplary embodiment. FIG. 7A is a sectionalview, FIG. 7B is a perspective view, and FIG. 8 is a conceptual viewillustrating the surface structure of the glass substrate used in themillimeter wave module in FIG. 7.

[0067] A millimeter wave module comprising a low-loss filter configuredwith two cavity resonators is described.

[0068] In FIG. 7, a silicon substrate 401 is provided with cavityes 402a and 402 b formed by anisotropic etching. Metal ground layers 403 a and403 b are deposited as ground faces on the bottom and side faces of eachcavity 402 a and 402 b. First and second coplanar waveguides 408 a and408 b connected between metal ground layers 403 a and 403 b of eachcavity are formed on the surface of a silicon single crystal substrate401. The ground metal is formed on substantially the entire face of thesilicon substrate 401, as shown in FIG. 7B by the slanted line, so as tobe insulated from the first and second coplanar waveguides 408 a and 408b.

[0069] On one face of the glass substrate 407, third and fourth coplanarwaveguides 409 a and 409 b, and a fifth coplanar waveguide patterning410 are provided. Ground metal is formed on substantially the entirebottom face of the glass substrate 407, as shown in FIG. 8 by theslanted line, except for areas where the coplanar waveguides 409 a, 409b, and 410 are formed.

[0070] Two windows 411 a formed on the silicon substrate 401 and twowindows 411 b formed on the glass substrate 407 are the portions wherethe ground metal is removed. The silicon substrates 401 and glasssubstrate 407 are bonded by anodic bonding at these windows.

[0071] The two spaces enclosed by the cavityes 402 a and 402 b and theground metal formed on the glass substrate act as cavity resonatorswhich resonate at frequencies determined by the condition that half thewavelength in free space is nearly equal to the lengths of the cavityes402 a or 402 b. These two cavity resonators are connected by the fifthcoplanar waveguide wiring 410 provided on the glass substrate 407. Toform an I/O terminal on the silicon substrate 401, the third coplanarwaveguide 409 a is connected with a cavity resonator with an air layer404 a, and the fourth coplanar waveguide 409 b is connected with acavity resonator with an air layer 404 b. This completes the cavityresonator filter configured with coplanar waveguides using the first andsecond coplanar waveguides 408 a and 408 b as I/O terminals.

[0072] Since the Q value of the cavity resonator is high, a low-lossfilter is achievable. In addition, the height of the air layer 404 ishighly accurate because the silicon substrate 401 and glass substrate407 are bonded at the windows 411 by anodic bonding, achieving theintended accurate resonance frequency.

[0073] Furthermore, since the I/O terminal has a coplanar structure,connection with other components such as an MMIC is easily achievable.

[0074] Consequently, an inexpensive radio apparatus is realized byemploying a millimeter wave module manufactured according to the abovesimple method.

[0075] This exemplary embodiment employs anodic bonding as the methodfor bonding the silicon substrate 401 and glass substrate 407. However,it is apparent that the mounting method using Au micro bumps, as inother exemplary embodiments, is applicable.

[0076] Eighth Exemplary Embodiment

[0077]FIG. 9 shows a radio apparatus in an eighth exemplary embodimentof the present invention. It is a conceptual view illustratingcommunications among multiple radio apparatuses employing the millimeterwave module described in the first to seventh exemplary embodiments.

[0078] As shown in FIG. 9, a small but high-performance millimeter wavemodule manufactured according to a simple method described in the firstto seventh exemplary embodiments is built in RF section of each radioapparatus. Accordingly, a small inexpensive radio apparatus isachievable.

[0079] As described above, the present invention enables a low-lossfilter on a semi-flat structure to be achieved using a simple processingmethod, and also facilitates connection with other components such as anMMIC. Thus, the advantageous effects of realizing a millimeter wavemodule satisfying both the requirements of smaller size and higherperformance, and an inexpensive radio apparatus employing suchmillimeter wave module are achieved.

[0080] The exemplary embodiments of the present invention describe anexample of connection through Au microbumps as a method for mountingcomponents such as MMICS. However, other surface mounting technologies,including flip-chip mounting through solder bumps, are similarlyapplicable.

[0081] The exemplary embodiments of the present invention also describean example of processing cavityes on a silicon substrate usinganisotropic etching. Other processing method such as dry etching issimilarly applicable.

What is claimed is:
 1. A millimeter wave module comprising: 1) a firstsubstrate having a face, said first substrate further having: a) a firstcavity with bottom and side faces; b) a conductor on said bottom andside faces of said first cavity; c) a connection part on said face ofsaid first substrate and around said first cavity, said connection partbeing electrically connected with said conductor; d) an air layer insaid first cavity; and 2) a second substrate having a face, said secondsubstrate being a dielectric substrate and having: e) a microstripfilter having metal patterning on said face of said second substrate;and f) a connection part connected to said metal patterning; said secondsubstrate mounted to said first substrate by connecting the connectionpart of said first substrate with said connection part connected to saidmetal patterning, with said metal patterning facing said air layer insaid first cavity and covering said first cavity.
 2. The millimeter wavemodule as defined in claim 1 further comprising, a millimeter wavecomponent having a face, said millimeter wave component having aconnection part on said face thereof, and a second cavity in said firstsubstrate with an air layer therein, wherein said millimeter wavecomponent is mounted on said first substrate by connecting saidconnection part of said millimeter wave component with said connectionpart of said first substrate, with said millimeter wave component facingsaid air layer in said second cavity on said first substrate andcovering said second cavity.
 3. The millimeter wave module as defined inclaim 1 , said second substrate further comprising: g) at least one of acavity and a hole; h) a connection part formed on a flat face around atleast one of said cavity and hole; and i) an air layer in said cavity.4. The millimeter wave module as defined in claim 3 , further comprisinga millimeter wave component, said millimeter wave component comprising aconnection part on its one flat face; wherein said millimeter wavecomponent is mounted on said second substrate by connecting saidconnection part on said one flat face with said connection part providedaround at least one of said cavity and hole on said second substrate ina way to face the air layer in at least one of said cavity and hole onsaid second substrate and cover at least one of said cavity and hole. 5.The millimeter wave module as defined in claim 1 , wherein said firstsubstrate comprising: a third substrate having at least one throughhole; a fourth substrate having a number of through holes not greaterthan a number of through holes on said third substrate; and a fifthsubstrate having no through hole at least at an area of said throughhole on said fourth substrate, wherein said through hole of said thirdsubstrate is said first cavity.
 6. The millimeter wave module as definedin claim 5 , wherein said fifth substrate has a metal layer on a facethereof which contacts said fourth substrate.
 7. The millimeter wavemodule as defined in claim 5 , wherein said fifth substrate is of ametal.
 8. The millimeter wave module as defined in claim 1 , whereinsaid first substrate is of a silicon single crystal substrate, and saidcavity is formed by anisotropic etching.
 9. The millimeter wave moduleas defined in claim 1 , wherein said first substrate is of a siliconsubstrate, and said cavity is formed by dry etching.
 10. The millimeterwave module as defined in claim 6 , wherein said third, fourth, andfifth substrates are one of a ceramic, BCB (benzocyclobutene), andpolyimide.
 11. The millimeter wave module as defined in claim 7 ,wherein said third and fourth substrates are one of a ceramic, BCB(benzocyclobutene), and polyimide.
 12. The millimeter wave module asdefined in claim 1 , wherein said first and second substrates aremutually connected by said connection part of said first substrate andsaid connection part of said second substrate applying flip-chipmounting technology.
 13. The millimeter wave module as defined in claim1 , wherein said second substrate has an opposite face which opposessaid face having said metal patterning, said second substrate furthercomprising: a conductor on said opposite face; and a through holeelectrically connecting said conductor on said opposite face and theconnection part connected to said metal patterning.
 14. A millimeterwave module comprising: 1) a first substrate having: a) at least firstand second cavityes with bottom and side faces; b) a conductor on saidbottom and side faces of said first and second cavityes; c) a firstcoplanar waveguide around said first cavity, said first coplanarwaveguide being electrically connected to said conductor in said firstcavity; d) a second coplanar waveguide around said second cavity , saidsecond coplanar waveguide being electrically connected to said conductorin said second cavity; e) a metal layer being electrically insulatedfrom said coplanar waveguides in c) and d); and f) an air layer in eachof said first and second cavityes; and 2) a second substrate being adielectric substrate having: g) a first coplanar waveguide formed at aposition corresponding to said first coplanar waveguide around saidfirst cavity; h) a second coplanar waveguide formed at a positioncorresponding to said second coplanar waveguide around said secondcavity; i) a third coplanar waveguide formed at a position correspondingto an interval between said first and second cavityes: j) a metal layerelectrically insulated from said coplanar waveguides in g), h), and i);wherein said coplanar waveguides in g) and h) face said coplanarwaveguides in c) and d) on said first substrate and are electricallyconnected; said metal layer in j) faces said air layer in each of saidfirst and second cavityes on said first substrate and covers saidcavityes; and said metal layers in j) and e) are electrically connected;and said first and second cavityes form cavity resonators.
 15. Amillimeter wave module comprising: a first silicon single crystalsubstrate; a plurality of rectangular cavityes formed by anisotropicetching on said first silicon single crystal substrate, said cavityeshaving bottom and side faces; a coplanar waveguide on said first siliconsingle crystal substrate; metal patterning on said first silicon singlecrystal substrate, said metal patterning connecting between saidcavityes by a coplanar waveguide; a conductor formed on said bottom andside faces of each of said cavityes as a ground plane; and a firstdielectric substrate having a metal patterning of a microstrip filter ona face thereof; said metal patterning of said microstrip filter facesand covers one cavity of said plurality of cavityes on said firstsilicon single crystal substrate; and an MMIC mounted on said firstsilicon single crystal substrate to cover another of said plurality ofcavityes on said first silicon single crystal substrate.
 16. Themillimeter wave module as defined in claim 15 , wherein Au bumps areprovided to mount said first dielectric substrate and MMIC to said firstsilicon single crystal substrate.
 17. The millimeter wave module asdefined in claim 15 , wherein said first dielectric substrate has a rearplane and a conductor on said rear plane as a ground face; and saidground face of said first dielectric substrate and said ground plane ofsaid first silicon single crystal substrate are connected by a throughhole provided on said first dielectric substrate.
 18. A millimeter wavemodule comprising: a multi-layer ceramic substrate including a firstceramic substrate with a rectangular hole bonded to a second ceramicsubstrate without a hole, a plurality of rectangular cavityes formed onsaid multi-layer ceramic substrate, said cavityes having bottom and sidefaces; a coplanar waveguide on said multi-layer ceramic substrate; metalpatterning on said multi-layer ceramic substrate, said metal patterningconnected between said cavityes by a coplanar waveguide; a conductorformed on said bottom and side faces of each of said cavityes as aground plane; a first dielectric substrate having a metal patterning ofa microstrip filter on a face thereof; said metal patterning of saidmicrostrip filter faces and covers one cavity of said plurality ofcavityes on said multi-layer ceramic substrate; and an MMIC mounted onsaid multi-layer ceramic substrate to cover another of said plurality ofcavityes on said multi-layer ceramic substrate.
 19. A millimeter wavemodule comprising: a multi-layer substrate including a first substrateof BCB (benzocyclobutene) with a rectangular hole bonded to a secondsubstrate of a ceramic without a hole, a plurality of rectangularcavityes formed on said multi-layer substrate, said cavityes havingbottom and side faces; a coplanar waveguide on said multi-layersubstrate; metal patterning on said multi-layer substrate, said metalpatterning connected between said cavityes by a coplanar waveguide; aconductor formed on said bottom and side faces of each of said cavityesas a ground plane; a first dielectric substrate having a metalpatterning of a microstrip filter on a face thereof, said metalpatterning of said microstrip filter faces and covers one cavity of saidplurality of cavityes on said multi-layer substrate; and an MMIC mountedon said multi-layer substrate to cover another of said plurality ofcavityes on said multi-layer substrate.
 20. A millimeter wave modulecomprising: a multi-layer substrate including a first substrate ofpolyimide with a rectangular hole bonded to a second substrate of aceramic without a hole, a plurality of rectangular cavityes formed onsaid multi-layer substrate, said cavityes having bottom and side faces;a coplanar waveguide on said multi-layer substrate; metal patterning onsaid multi-layer substrate, said metal patterning connected between saidcavityes by a coplanar waveguide; a conductor formed on said bottom andside faces of each of said cavityes as a ground plane; a firstdielectric substrate having a metal patterning of a microstrip filter ona face thereof, said metal patterning of said microstrip filter facesand covers one cavity of said plurality of cavityes on said multi-layersubstrate; and an MMIC mounted on said multi-layer substrate to coveranother of said plurality of cavityes on said multi-layer substrate. 21.The millimeter wave module as defined in claim 18 , wherein a metallayer is provided as a ground plane on the entire bonded face betweensaid first and second substrates.
 22. A millimeter wave modulecomprising: a multi-layer substrate including a first substrate of aceramic with a rectangular hole bonded to a second substrate of aconductive metal without a hole, a plurality of rectangular cavityesformed on said multi-layer substrate, said cavityes having bottom andside faces; a coplanar waveguide on said multi-layer substrate; metalpatterning on said multi-layer substrate, said metal patterningconnected between said cavityes by a coplanar waveguide; a conductorformed on said bottom and side faces of each of said cavityes as aground plane; a first dielectric substrate having a metal patterning ofa microstrip filter on a face thereof, said metal patterning of saidmicrostrip filter faces and covers one cavity of said plurality ofcavityes on said multi-layer substrate; and an MMIC mounted on saidmulti-layer substrate to cover another of said plurality of cavityes onsaid multi-layer substrate.
 23. A millimeter wave module comprising: adielectric substrate having on a face thereof metal patterning by acoplanar waveguide, metal patterning of a microstrip filter, and arectangular hole; and a silicon single crystal substrate in which acavity is formed by anisotropic etching, and a ground conductor isdeposited in on a face of said cavity said silicon single crystalsubstrate is mounted to said dielectric substrate to cover the metalpatterning of the microstrip filter on said dielectric substrate; and anMMIC is mounted to said dielectric substrate to cover said rectangularhole provided on said dielectric substrate.
 24. A millimeter wave modulecomprising: a silicon single crystal substrate; first and secondcavityes formed by anisotropic etching on said silicon single crystalsubstrate, said cavityes having bottom and side faces; a conductorformed on said bottom and side faces of said first and second cavityesas a ground plane; a first and second coplanar waveguides as I/O lines;a dielectric substrate having a conductor thereon as a ground plane;first and second cavity resonators provided by bonding said dielectricsubstrate, and said silicon substrate to cover said first and secondcavityes; a third coplanar waveguide on a part of said ground planeprovided on said dielectric substrate, said third coplanar waveguideconnecting said first coplanar waveguide and said first cavityresonator; a fourth coplanar waveguide connecting said first and secondcavity resonators; and a fifth coplanar waveguide connecting said secondcoplanar waveguide and said second cavity resonator.
 25. A radioapparatus employing the millimeter wave module defined in claim 1 . 26.A radio apparatus employing the millimeter wave module defined in claim14 .
 27. A radio apparatus employing the millimeter wave module definedin claim 15 .
 28. A radio apparatus employing the millimeter wave moduledefined in claim 23 .
 29. A radio apparatus employing the millimeterwave module defined in claim 24 .
 30. The millimeter wave module asdefined in claim 5 wherein said third, fourth and fifth substrates areone of a ceramic, BCB (benzocyclobutene), and polyimide.